K1 AEG boxed – KTD T1 boxed – Siemens & Halske K1 of 1916

Description

This section shows a four tubular made triode by Siemens & Halske as well as AEG and KTD, please refer to photos and descritoion. The Siemens &Halske K1 tube looks very similar to the AEG K1 but has a rectangular grid and later a tightly stretched filament. They had a patent on it. The KTD Stromverstarker type T1 shaes the same design Benefit was an even emission across the whole filament. In the AEG K1 emission had a maximum at the top of the filament and thus it burned at this spot in most cases after several hours of use. Siemens also used a punched grid whereas AEG grids are made from a spiral.